Research On Inter-region Accessibility Model Based On Clustering

Accessibility has different concepts in different disciplines and plays an important role in traffic planning,economic development and social and population mobility.The traditional reachability evaluation model is mainly based on rigid traffic network.It has the advantages of simple process,wide range of use and clear explanation of white box model to study the potential influence of hidden factors on accessibility.At the same time,it is difficult to quantify the factors,there is no comparability between the results of different models,the open-loop evaluation emphasizes the results and the factor analysis,and only mining the hidden characteristics of the indicators but neglecting the dominant characteristics of the indicators.Therefore,this paper extends the concept of reachability through literature analysis and conceptual analysis.For the attractiveness of different regional factors,and based on the population,transportation,economy and some social factors,using the statistical yearbook data to establish the corresponding implicit index system,Through PCA weighted K-MEDOIDS clustering algorithm to study the impact of reachability on Shaanxi regional economic development,traffic change population flow,the study found that:1)The clustering results show that the regional accessibility of Shaanxi can be divided into four levels and three levels: the developed region represented by Xian Xianyang,the economic characteristic area represented by Yulin and Hanzhong,and the poorer area represented by Shangluo.Taking Xi’an and Shangluo as objects,this paper analyzes the influence of different factors on the accessibility difference between them,and finds that: Xi’an,due to education,traffic,Medical treatment and economy have theabsolute advantage in Shaanxi region is the main reason that cause Xi’an region to reach obviously higher than other region,and Shangluo area because of the industry structure is single,the transportation inside the region is not developed,The Development of Expressway and the siphon of Xi’an to the surrounding area The effect leads to the low degree of accessibility in Shangluo area.2)The results of 2000,2005,2010 and 2015 are analyzed by clustering.It is found that the regional accessibility of Shaanxi is stable on the time axis,the development of traffic from 2000 to 2008 is the main driving force of the change of accessibility,and the expansion of traffic elements from 2008 to 2012 has entered a gentle period.From2012 to 2015,the national policy is the main motive force of the reachability change,and the change of the national policy has obvious short-term effect on the reachability change.3)Based on the regional radiation theorem,the similarities and differences between the cluster model and the gravity resistance model are compared,and based on the concept of reachability extension,the regional radiation theorem is used to analyze the unipolar effect of reachability in Xi’an,the inherent geographical advantage,the accumulation of historical factors and the education.Monopolization of resources such as medical treatment is a positive factor in the unipolarization effect of Xi’an in Shaanxi region.However,because there is no complementarity between the development elements and the surrounding areas,it is difficult to eliminate the peripheral transfer of the elements,so a large number of college graduates are graduating every year.The main power source of the future reachability change of an.4)By comparing the advantages and disadvantages of reachability clustering model and gravity resistance model,it is found that the gravity resistance model is suitable for the case of simple topological network and single and definite influencing factors,and the clustering model is suitable for the analysis of large sample and multi-dimensional index.The index weighting process is the process of pre-analysis of the importance of indicators by using statistics,so the index weighted clustering can better reflect the change of reachability.